Rotary plastic blow molding machines conventionally include a structural frame or wheel mounted on a base for rotation about a horizontal rotational axis. The wheel includes a frame that supports a plurality of mold stations, each of which are mounted around the circumference of the machine, and each of which has a pair of mold supports for mounting a pair of mold portions of a mold. A continuously extruded parison is guided between open mold halves. With rotation, the molds close on the parison, the parison is blown, the molds open to eject containers, and the cycle is repeated. The molds are continuously rotated at high speed to produce containers in high volumes. These machines are expensive to construct and operate. As many as twenty-four or more new molds may be required. Change-over to a different style container is expensive and time-consuming due to the need to build and install a set of new molds on the supports.
One such machine is disclosed in U.S. Pat. No. 3,764,250 issued to Waterloo. Waterloo discloses a blow molding machine which includes a shaft, through which air and fluid pass, which extends through the wheel. A pair of side means are provided, which are parallel to each other and extend transversely to the axis of the shaft. Extending between the side means, in even, circumferentially-spaced relationship to each other, are pairs of similar guide rods, which are firmly secured at the ends thereof, respectively, to the side means. Mounted upon each pair of guide rods is a pair of similar complementary jaws, which are provided with opposing vertical faces against which the mold dies are firmly mounted by appropriate attaching means, such as bolts or the like, not shown, in accordance with conventional practice in blow molding machines. Thus, the basic elements of the wheel are the side means and the guide rods which extend therebetween and are connected firmly thereto. The support of the side means, and other components on the continuous shaft, is an essential feature of the machine.
Because of the supports and shafts required to properly operate the machines, the machines are complicated to manufacture and require significant expertise and time to repair or replace the mold clamp assemblies. It would, therefore, be beneficial to provide a blow molding machine in which the components are more modular, thereby allowing the components to be easily repaired or replaced when a change-over to a different style container is required.